Channel Discovery in a Small-Cell Network

ABSTRACT

During operation, the radio node may, using a first interface circuit, listen for transmissions from one or more second radio nodes. Based at least in part on the transmissions, the radio node may determine a first list of discovered channels associated with the radio node and the one or more second radio nodes. Then, the radio node may, using a second interface circuit, provide the first list of discovered channels to the one or more second radio nodes. Moreover, the radio node may, using the second interface circuit, receive one or more second lists of discovered channels from the one or more second radio nodes. Next, the radio node may aggregate the first list of discovered channels and the second list of discovered channels into a list of active channels. Furthermore, the radio node may, using the first interface circuit, provide the list of active channels to an electronic device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119(e) to: U.S.Provisional Application Ser. No. 62/987,312, “Channel Discovery in aSmall-Cell Network,” filed on Mar. 9, 2020, by Ramesh Rayanki, et al.,the contents of which are herein incorporated by reference.

FIELD

The described embodiments relate to techniques for communicatinginformation among electronic devices. Notably, the described embodimentsrelate to techniques for aggregating and distributing a list of channelsassociated with radio nodes.

BACKGROUND

While many electronic devices communicate with each other via largenetworks owned by a network operator, small-scale networks associatedwith entities (such as a company or an organization) are increasinglycommon. In principle, the small-scale network complements the serviceoffered by the network operator and can offer improved communicationperformance, such as in a particular venue or environment. In practice,the communication performance of small-scale networks (and largenetworks) is often constrained by resources, such as bandwidth in ashared communication channel.

In order to address these constraints, additional bands of frequenciesare being used by large networks and small-scale networks. For example,the shared-license-access band of frequencies near 3.5 GHz (notably, the150 MHz of bandwidth between 3.55 GHz and 3.7 GHz) is being used forgeneral-purpose communication. This shared-license-access band offrequencies is referred to as ‘Citizens Broadband Radio Service’ orCBRS.

In CBRS, a radio node (which is sometimes referred to as a ‘CitizensBand Service Device’ or CBSD) may provide a grant request to a SAS (acloud-based service that manages wireless communication in the CBRS) toreserve a portion of the spectrum or bandwidth in theshared-license-access band of frequencies, in a particular geographicregion, for its use. For example, a radio node may request a grant toreserve 5 MHz of spectrum from the SAS in a particular geographicregion. If the requested portion of the spectrum is available, the SASmay provide a grant response to the radio node with approval of a grantfor the requested portion of the spectrum. Then, the radio node mayprovide a heartbeat request to the SAS to request authorization totransmit in the granted portion of the spectrum. When the radio nodereceives a subsequent heartbeat response from the SAS, the radio node isauthorized to transmit in the granted portion of the spectrum.

Because the portions of the spectrum in CBRS are dynamically allocated,the channels or frequencies used by the radio nodes in a small-scalenetwork are not deterministic. Indeed, in general, the channels orfrequencies may vary as a function of time. Consequently, it is oftendifficult to preprogram the channels or frequencies used in asmall-scale network (such as at a venue or location) into electronicdevices (such as cellular telephones). Therefore, in order to determinethe channels or frequencies, an electronic device may need to perform ascan of the full CBRS spectrum of 150 MHz, which is time-consuming,increases the power consumption of the electronic device, and canadversely impact the communication performance of the electronic deviceand, thus, the user experience.

SUMMARY

In a first group of embodiments, a radio node that aggregates a list ofactive channels is described. This radio node includes: a first node orconnector; a second node or connector; a first interface circuit,coupled to the first node or connect, that communicates using wirelesscommunication; and a second interface circuit, coupled to the secondnode or connector, that communicates with one or more second radio nodesin a network. During operation, the radio node may, using the firstinterface circuit, listen for transmissions associated with the one ormore second radio nodes. Based at least in part on the transmissions,the radio node may determine a first list of discovered channelsassociated with the radio node and the one or more second radio nodes.Then, the radio node may, using the second interface circuit, providethe first list of discovered channels addressed to the one or moresecond radio nodes. Moreover, the radio node may, using the secondinterface circuit, receive one or more second lists of discoveredchannels associated with the one or more second radio nodes. Next, theradio node may aggregate the first list of discovered channels and thesecond list of discovered channels into the list of active channels.Furthermore, the radio node may, using the first interface circuit,provide the list of active channels addressed to an electronic device.

Note that the radio node may provide the list of first discoveredchannels using a multicast message.

Moreover, the network may include a small cell.

Furthermore, the channels may be portions of a spectrum in ashared-license-access band of frequencies. For example, the channels maybe included in a Citizens Broadband Radio Service.

Additionally, the radio node may, using the second interface circuit,provide the list of discovered channels and/or the list of activechannels addressed to a computer. Note that the computer may include acontroller for the radio node and the one or more second radio nodes.Consequently, the computer may be different from a SAS.

In some embodiments, the second interface circuit may use wiredcommunication.

Moreover, the radio node may include: an Evolved Node B (eNodeB), aUniversal Mobile Telecommunications System (UMTS) NodeB and radionetwork controller (RNC), a New Radio (NR) gNB or gNodeB (whichcommunicates with the network with a cellular-telephone communicationprotocol that is other than Long Term Evolution), etc.

Another embodiment provides the computer.

Another embodiment provides the electronic device. After receiving thelist of active channels, the electronic device may perform a scan of aband of frequencies (such as a shared-license-access band offrequencies) based at least in part on the list of active channels. Forexample, the scan may be restricted to channels in the list of activechannels.

Another embodiment provides a computer-readable storage medium withprogram instructions for use with the radio node, the computer or theelectronic device. When executed by the radio node, the computer or theelectronic device, the program instructions cause the radio node toperform at least some of the aforementioned operations in one or more ofthe preceding embodiments.

Another embodiment provides a method, which may be performed by theradio node, the computer or the electronic device. This method includesat least some of the aforementioned operations in one or more of thepreceding embodiments.

In a second group of embodiments, a radio node that provides a list ofactive channels is described. This radio node includes: a first node orconnector; a second node or connector; a first interface circuit,coupled to the first node or connector, that communicates using wirelesscommunication; and a second interface circuit, coupled to the secondnode or connector, that communicates with a computer. During operation,the radio node may, using the second interface circuit, provide,addressed to the computer, information specifying a channel used by theradio node. Then, the radio node may, using the second interfacecircuit, receive, associated with the computer, the list of activechannels associated with the radio node and one or more second radionodes in a network. Next, the radio node may, using the first interfacecircuit, provide the list of active channels addressed to an electronicdevice.

Moreover, the network may include a small cell.

Furthermore, the channels may be portions of a spectrum in ashared-license-access band of frequencies. For example, the channels maybe included in a Citizens Broadband Radio Service.

Additionally, the computer may include a controller for the radio nodeand the one or more second radio nodes. Consequently, the computer maybe different from a SAS.

In some embodiments, the second interface circuit may use wiredcommunication.

Moreover, the radio node may include: an Evolved Node B (eNodeB), aUniversal Mobile Telecommunications System (UMTS) NodeB and radionetwork controller (RNC), a New Radio (NR) gNB or gNodeB (whichcommunicates with a network with a cellular-telephone communicationprotocol that is other than Long Term Evolution), etc.

Another embodiment provides the computer. This computer may aggregatethe information from the radio node and the one or more second radionodes in the network into the list of active channels, which is thenprovided to the radio node and the one or more second radio nodes.

Another embodiment provides the electronic device. After receiving thelist of active channels, the electronic device may perform a scan of aband of frequencies (such as a shared-license-access band offrequencies) based at least in part on the list of active channels. Forexample, the scan may be restricted to channels in the list of activechannels.

Another embodiment provides a computer-readable storage medium withprogram instructions for use with the radio node, the computer or theelectronic device. When executed by the radio node, the computer or theelectronic device, the program instructions cause the radio node toperform at least some of the aforementioned operations in one or more ofthe preceding embodiments.

Another embodiment provides a method, which may be performed by theradio node, the computer or the electronic device. This method includesat least some of the aforementioned operations in one or more of thepreceding embodiments.

This Summary is provided for purposes of illustrating some exemplaryembodiments, so as to provide a basic understanding of some aspects ofthe subject matter described herein. Accordingly, it will be appreciatedthat the above-described features are examples and should not beconstrued to narrow the scope or spirit of the subject matter describedherein in any way. Other features, aspects, and advantages of thesubject matter described herein will become apparent from the followingDetailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram illustrating an example of communication amonga computer, radio nodes and electronic devices in a system in accordancewith an embodiment of the present disclosure.

FIG. 2 is a flow diagram illustrating an example of a method foraggregating a list of active channels using a radio node in FIG. 1 inaccordance with an embodiment of the present disclosure.

FIG. 3 is a drawing illustrating an example of communication among theelectronic devices in FIG. 1 in accordance with an embodiment of thepresent disclosure.

FIG. 4 is a drawing illustrating an example of a technique foraggregating a list of active channels in accordance with an embodimentof the present disclosure.

FIG. 5 is a flow diagram illustrating an example of a method forproviding a list of active channels using a radio node in FIG. 1 inaccordance with an embodiment of the present disclosure.

FIG. 6 is a drawing illustrating an example of communication among theelectronic devices in FIG. 1 in accordance with an embodiment of thepresent disclosure.

FIG. 7 is a drawing illustrating an example of a technique for providinga list of active channels in accordance with an embodiment of thepresent disclosure.

FIG. 8 is a drawing illustrating an example of channel discovery inaccordance with an embodiment of the present disclosure.

FIG. 9 is a drawing illustrating an example of channel discovery inaccordance with an embodiment of the present disclosure.

FIG. 10 is a block diagram illustrating an example of an electronicdevice in accordance with an embodiment of the present disclosure.

Note that like reference numerals refer to corresponding partsthroughout the drawings. Moreover, multiple instances of the same partare designated by a common prefix separated from an instance number by adash.

DETAILED DESCRIPTION

In a first group of embodiments, a radio node (such as an eNode-B) thataggregates a list of active channels is described. During operation, theradio node may, using a first interface circuit, listen fortransmissions from one or more second radio nodes. Based at least inpart on the transmissions, the radio node may determine a first list ofdiscovered channels associated with the radio node and the one or moresecond radio nodes. Then, the radio node may, using a second interfacecircuit, provide the first list of discovered channels to the one ormore second radio nodes. Moreover, the radio node may, using the secondinterface circuit, receive one or more second lists of discoveredchannels from the one or more second radio nodes. Next, the radio nodemay aggregate the first list of discovered channels and the second listof discovered channels into the list of active channels. Furthermore,the radio node may, using the first interface circuit, provide the listof active channels to an electronic device (such as a cellulartelephone).

Alternatively or additionally, in a second group of embodiments, a radionode that provides a list of active channels is described. Duringoperation, the radio node may, using a second interface circuit,provide, to a computer, information specifying a channel used by theradio node. Then, the radio node may, using the second interfacecircuit, receive, from the computer, the list of active channelsassociated with the radio node and one or more second radio nodes in anetwork. Next, the radio node may, using a first interface circuit,provide the list of active channels to an electronic device.

By aggregating and/or providing the list of active channels, thesecommunication techniques may reduce a scan time in a band of frequencies(such as a shared-license-access band of frequencies, e.g., the CBRS)performed by the electronic device. For example, the electronic devicemay perform a scan restricted to channels in the list of activechannels. In the process, the communication techniques may improvebattery life of the electronic device and/or communication performanceof the electronic device. Consequently, the communication techniques mayimprove a user experience when using the electronic device and/orcommunicating with the radio node.

We now describe some embodiments of the communication techniques. Acellular-telephone network may include base stations (and associatedcell towers) that implement so-called ‘macrocells.’ These macrocells mayfacilitate communication with hundreds of users (such as hundreds ofcellular telephones) over distances of kilometers. In general, thepositioning of the cell towers (and the antennas) is carefully designedand optimized to maximize the performance of the cellular-telephonenetwork (such as the throughput, the capacity, the block error rate,etc.) and to reduce crosstalk or interference between the signalstransmitted by different cell towers and/or different macrocells. Smallcells are generally radio access nodes providing lower power thanmacrocells and therefore providing smaller coverage areas thanmacrocells. It is common to subcategorize ‘small cells’ even further byascribing relative general ranges. For example, a ‘microcell’ might havea range of less than 2 kilometers, a “picocell” less than 200 meters,and a ‘femtocell’ on the order of 10 meters. These descriptions are forgeneral relative comparison purposes and should not be limiting on thescope of the disclosed embodiments of the communication techniques.

However, there are often gaps in the coverage offered by macrocells.Consequently, some users operate local transceivers that provideshort-range communication in the cellular-telephone network. Theseso-called ‘femto cells’ provide short-range communication (e.g., up to10 m) for a few individuals.

In addition, larger organizations (such as those with 50-60 users, whichis a non-limiting numerical example) may operate local transceivers thatprovide communication in the cellular-telephone network over a range of100 m. This intermediate-range coverage in the cellular-telephonenetwork can be typically referred to as a ‘small cell’ as well.

In a cellular-telephone network, cellular telephones or, more generally,electronic devices associated with a mobile network operator can bepre-programmed with a list of active channels and bands of frequencies.Unless a cellular telephone is roaming, his information may allow thecellular telephone to rapidly connect with the cellular-telephonenetwork. However, because the channels used by radio nodes in a smallcell are dynamically allocated (and, thus, can vary as a function oftime), it typically not possible to pre-program a list of activechannels into electronic devices that use the small cell. Without thisinformation, a cellular telephone or an electronic device may need toscan the entire band of frequencies associated with the small cell todiscover the active channels, which is time-consuming and increasespower consumption. For example, the CBRS includes 150 MHz, which caninclude up to thirty 5 MHz channels.

These challenges are addressed in the communication techniques describedbelow. Notably, the radio nodes in a small cell may collaborativelyaggregate a list of active channels, which is then disseminated to theelectronic devices. Alternatively or additionally, the radio nodes in asmall cell may provide information specifying their granted andallocated channels to computer, which aggregates this information intothe list of active channels. Then, the computer may provide the list ofactive channels to the radio nodes, which disseminate it to theelectronic devices. Consequently, the communication techniques mayprovide a distributed and/or a centralized approach for aggregating thelist of active channels. Moreover, using the list of active channels, anelectronic device may restrict a scan in a band of frequenciesassociated with the small cell (e.g., to the channels in the list ofactive channels), thereby reduced the scan time and the powerconsumption of the electronic device.

In the discussion that follows, Long Term Evolution or LTE (from the 3rdGeneration Partnership Project of Sophia Antipolis, Valbonne, France) isused as an illustration of a data communication protocol in acellular-telephone network or a network that is used duringcommunication between one or more radio nodes and an electronic device.Consequently, eNodeBs or eNBs are used as illustrative examples of theradio nodes. However, a wide variety of communication techniques orprotocols may be readily used for the various embodiments. For example,an electronic device and a radio node may communicate frames or packetsin accordance with a wireless communication protocol, such as anInstitute of Electrical and Electronics Engineers (IEEE) 802.11 standard(which is sometimes referred to as ‘Wi-Fi,’ from the Wi-Fi Alliance ofAustin, Tex.), Bluetooth (from the Bluetooth Special Interest Group ofKirkland, Wash.), a cellular-telephone or data network (such as using athird generation or 3G communication protocol, a fourth generation or 4Gcommunication protocol, e.g., LTE, LTE Advanced or LTE-A, a fifthgeneration or 5G communication protocol, or other present or futuredeveloped advanced cellular communication protocol) and/or another typeof wireless interface (such as communication protocol). Thus, the radionodes may include: an eNodeB, a UMTS NodeB and RNC, an NR gNB or gNodeB,etc.

Moreover, a radio node may communicate with other radio nodes and/orcomputers in a network using a wired communication protocol, such as anIEEE 802.3 standard (which is sometimes referred to as ‘Ethernet’)and/or another type of wired interface. In the discussion that follows,Ethernet is used as an illustrative example.

FIG. 1 presents a block diagram illustrating an example of communicationamong electronic devices according to some embodiments. Notably, radionodes 110 can communicate LTE data frames or packets using LTE with anelectronic device 112 (which is sometimes referred to as ‘userequipment’ or UE, such as a cellular telephone and, more generally, aportable electronic device) in a communication environment 108 or avenue. Again, while LTE is used as an example of a cellular protocol,the embodiments herein are not so limited. Moreover, radio nodes 110 mayalso communicate (via wireless or wired communication, such as Ethernet,in network 114) with each other and with a computer 124 (such as a SAS)or a controller or management computer for radio nodes 110 (such as acontroller 126).

As described further below with reference to FIGS. 2-4, one or more ofradio nodes 110 may perform the communication techniques bycommunicating with other radio nodes 110 via network 114. Using radionode 110-1 as an example, this radio node may listen for wirelesstransmissions from at least some (such as one or more) of the remainingradio nodes 110. For example, radio node 110-1 may perform a networklisten. Based at least in part on the transmissions, radio node 110-1may determine a first list of discovered channels associated with radionode 110-1 and at least some of the remaining radio nodes 110, such as alist of the channels used by radio node 110-1 and at least some of theremaining radio nodes 110 in a band of frequencies (such as the CBRS) ina network (such as a small cell). Then, radio node 110-1 may provide,via network 114, the first list of discovered channels to one or more ofthe remaining radio nodes 110. Moreover, one or more of the remainingradio nodes 110 may also listen for wireless transmission and maydetermine second lists of discovered channels, which are provided, vianetwork 114, to other radio nodes 110. Consequently, radio node 110-1may receive, via network 114, one or more second lists of discoveredchannels from the one or more of the remaining radio nodes 110. Next,radio node 110-1 may aggregate the first list of discovered channels andthe second list of discovered channels into a list of active channelsthat are used by radio nodes 110 in the band of frequencies.Furthermore, radio node 110-1 may provide the list of active channels toan electronic device (such as electronic device 112) using wirelesscommunication.

Alternatively or additionally, as described below with reference toFIGS. 5-7, radio node 110-1 may provide, via network 114, informationspecifying one or more channels used by radio node 110-1 in the band offrequencies to a computer, such as controller 126. The remaining radiosnodes 110 may also provide, via network 114, similar information abouttheir channels to controller 126. Then, controller 126 may aggregate theinformation into a list of active channels that are used by radio nodes110 in the band of frequencies in the network. Moreover, controller 126may provide, via network 114, the list of active channels to radio nodes110. Consequently, radio node 110-1 may receive, via network 114, thelist of active channels. Next, radio node 110-1 may provide the list ofactive channels to an electronic device (such as electronic device 112)using wireless communication.

After receiving the list of active channels, electronic device 112 mayperform a scan in the band of frequencies based at least in part on thelist of active channels. For example, the scan may be restricted tochannels in the list of active channels.

In these ways, the communication techniques may allow electronic device112 to perform a more efficient and, thus, a faster scan in the band offrequencies. In addition to reducing the power consumption and improvingthe communication performance of electronic device 112, this capabilitymay reduce a time delay or latency for electronic device 112 to discovera particular radio node in radio nodes 110 and to establish a connectionwith this radio node.

In general, the wireless communication in FIG. 1 may be characterized bya variety of performance metrics, such as: a data rate for successfulcommunication (which is sometimes referred to as ‘throughput’), an errorrate (such as a retry or resend rate), a mean-square error of equalizedsignals relative to an equalization target, intersymbol interference,multipath interference, a signal-to-noise ratio, a width of an eyepattern, a ratio of number of bytes successfully communicated during atime interval (such as 1-10 s) to an estimated maximum number of bytesthat can be communicated in the time interval (the latter of which issometimes referred to as the ‘capacity’ of a communication channel orlink), and/or a ratio of an actual data rate to an estimated data rate(which is sometimes referred to as ‘utilization’).

During the communication in FIG. 1, radio nodes 110 and electronicdevice 112 may wirelessly communicate while: transmitting accessrequests and receiving access responses on wireless channels, detectingone another by scanning wireless channels, establishing connections (forexample, by transmitting connection requests and receiving connectionresponses), and/or transmitting and receiving frames that includepackets (which may include information as payloads).

As described further below with reference to FIG. 10, radio nodes 110and electronic device 112 may include subsystems, such as a networkingsubsystem, a memory subsystem and a processor subsystem. In addition,radio nodes 110 and electronic device 112 may include radios 118 in thenetworking subsystems. More generally, radio nodes 110 and electronicdevice 112 can include (or can be included within) any electronicdevices with the networking subsystems that enable radio nodes 110 andelectronic device 112 to wirelessly communicate with each other. Thiswireless communication can comprise transmitting access on wirelesschannels to enable electronic devices to make initial contact with ordetect each other, followed by exchanging subsequent data/managementframes (such as connection requests and responses) to establish aconnection, configure security options, transmit and receive frames orpackets via the connection, etc.

Moreover, as can be seen in FIG. 1, wireless signals 120 (represented bya jagged line) are transmitted by radios 118 in radio nodes 110 andelectronic device 112. For example, radio 118-1 in radio node 110-1 maytransmit information (such as frames or packets) using wireless signals120. These wireless signals are received by radios 118 in one or moreother electronic devices (such as radio 118-2 in electronic device 112).This may allow radio node 110-1 to communicate information to otherradio nodes 110 and/or electronic device 112. Note that wireless signals120 may convey LTE frames or packets.

In the described embodiments, processing a frame that includes packetsin radio nodes 110 and electronic device 112 may include: receiving thewireless signals with the frame; decoding/extracting the frame from thereceived wireless signals to acquire the frame; and processing the frameto determine information contained in the payload of the frame (such asthe packet).

Although we describe the network environment shown in FIG. 1 as anexample, in alternative embodiments, different numbers or types ofelectronic devices may be present. For example, some embodimentscomprise more or fewer electronic devices. As another example, inanother embodiment, different electronic devices are transmitting and/orreceiving frames that include packets.

We now describe embodiments of the method. FIG. 2 presents a flowdiagram illustrating an example of a method 200 for aggregating a listof available channels, which may be performed by a radio node (such asone of radio nodes 110 in FIG. 1). During operation, a first interfacecircuit in the radio node may listen for transmissions (operation 210)associated with the one or more second radio nodes. For example, theradio node may perform a network listen.

Based at least in part on the transmissions, the radio node maydetermine a first list of discovered channels (operation 212) associatedwith the radio node and the one or more second radio nodes. For example,the list of discovered channels may include channels that are used bythe radio node and the one or more second radio nodes.

Then, a second interface circuit in the radio node may provide the firstlist of discovered channels (operation 214) addressed to the one or moresecond radio nodes. For example, the list of discovered channels may beprovided using a multicast message. Moreover, the second interfacecircuit in the radio node may receive one or more second lists ofdiscovered channels (operation 216) associated with the one or moresecond radio nodes.

Next, the radio node may aggregate the first list of discovered channelsand the second list of discovered channels into the list of activechannels (operation 218). Furthermore, a first interface circuit in theradio node may provide the list of active channels addressed (operation220) to an electronic device.

Moreover, radio node and the one or more second radio nodes may be in anetwork, such as a small cell. Furthermore, the channels may be portionsof a spectrum in a shared-license-access band of frequencies. Forexample, the channels may be included in a CBRS.

In some embodiments, the second interface circuit may use wiredcommunication.

Note that the radio node may include: an eNodeB, a UMTS NodeB and RNC, aNew Radio (NR) gNB or gNodeB, etc.

In some embodiments, the radio node optionally performs one or moreadditional operations (operation 222). For example, the second interfacecircuit may provide the list of discovered channels and/or the list ofactive channels addressed to a computer. Note that the computer mayinclude a controller for the radio node and the one or more second radionodes. Consequently, the computer may be different from a SAS.

In some embodiments of method 200, there may be additional or feweroperations. Furthermore, the order of the operations may be changed,and/or two or more operations may be combined into a single operation.

Embodiments of the communication techniques are further illustrated inFIG. 3, which presents a drawing illustrating an example ofcommunication among radio nodes 110 and electronic device 112. In FIG.3, an interface circuit (IC) 310 in radio node 110-1 may listen forwireless transmissions 312 associated with one or more of radio nodes110-2, 110-3, or 110-4. For example, transmissions 312 may include oneor more packets or frames transmitted by one or more of radio nodes110-2, 110-3 or 110-4. Based at least in part on transmissions 312, theinterface circuit 310 may determine a list of discovered channels (LDC)314 associated with radio node 110-1 and one or more of radio nodes110-2, 110-3 or 110-4.

Then, interface circuit 310 may provide the list of discovered channels314 to interface circuit 316 in radio node 110-1, which may provide thelist of discovered channels 314 to one or more of radio nodes 110-2,110-3 or 110-4. For example, the list of discovered channels 314 may beprovided using a multicast message that is communicated using wiredcommunication. Moreover, radio nodes 110-2, 110-3 and/or 110-4 mayprovide one or more lists of discovered channels 318 (which werediscovered by radio nodes 110-2, 110-3 and/or radio node 110-4) to radionode 110-1.

After receiving the one or more lists of discovered channels 318,interface circuit 316 may provide the one or more lists of discoveredchannels 318 to interface circuit 310. Next, interface circuit 310 mayaggregate the list of discovered channels 314 and the one or more listsof discovered channels 318 into a list of active channels (LAC) 320. Forexample, aggregating the list of discovered channels 314 and the one ormore lists of discovered channels 318 may involve removing redundant orduplicated channels that were discovered by more than one of radio nodes110.

Furthermore, interface circuit 310 in radio node 110-1 may provide thelist of active channels 320 to electronic device 112. After receivingthe list of active channels 320, electronic device 112 may perform awireless scan 322 based at least in part on the list of active channels320.

While FIG. 3 illustrates communication between components usingunidirectional or bidirectional communication with lines having singlearrows or double arrows, in general the communication in a givenoperation in this figure may involve unidirectional or bidirectionalcommunication.

In some embodiments of the communication techniques, a radio nodeaggregates a list of active channels in a network, which is thenprovided to an electronic device (such as a cellular telephone) that isconnected to radio node. This is illustrated in FIG. 4, which presents adrawing illustrating an example of a technique for aggregating a list ofactive channels used by CBSDs 410 in the CBRS. Notably, CBSDs 410 maydetermine and exchange lists of discovered channels based at least inpart on transmissions from CBSDs 410. Using CBSD 110-1 as an example,CBSD 110-1 may aggregate the lists of discovered channels into the listof active channels, such as f₁, f₂, f₃ and f₄. Then, CBSD 110-1 mayprovide the list of active channels to an electronic device (such aselectronic device 112 in FIG. 1).

FIG. 5 presents a flow diagram illustrating an example of a method 500for providing a list of available channels, which may be performed by aradio node (such as one of radio nodes 110 in FIG. 1). During operation,a second interface circuit in the radio node may provide, addressed to acomputer, information specifying a channel (operation 510) used by theradio node. Then, a second interface circuit in the radio node mayreceive, associated with the computer, a list of active channels(operation 512) associated with the radio node and one or more secondradio nodes in a network. Next, a first interface circuit in the radionode may provide the list of active channels (operation 514) addressedto an electronic device.

Moreover, the network may include a small cell. Furthermore, thechannels may be portions of a spectrum in a shared-license-access bandof frequencies. For example, the channels may be included in a CitizensBroadband Radio Service.

Additionally, the computer may include a controller for the radio nodeand the one or more second radio nodes. Consequently, the computer maybe different from a SAS.

In some embodiments, the second interface circuit may use wiredcommunication.

Note that the radio node may include: an eNodeB, a UMTS NodeB and RNC, aNew Radio (NR) gNB or gNodeB, etc.

In some embodiments of method 500, there may be additional or feweroperations. Furthermore, the order of the operations may be changed,and/or two or more operations may be combined into a single operation.For example, instead of receiving information that specifies thechannels from one or more radio nodes, the computer may obtain theinformation from a SAS.

Embodiments of the communication techniques are further illustrated inFIG. 6, which presents a drawing illustrating an example ofcommunication among radio node s110, controller 126 and electronicdevice 112. In FIG. 6, an interface circuit (IC) 610 in radio node 110-1may provide information specifying a channel 612 used by radio node110-1 to controller 126. For example, the information may be providedusing wired communication. In addition, radio nodes 110-2 and 110-3 mayprovide similar information specifying channels 614 used by these radionodes to controller 126.

After receiving the information specifying channels 612 and 614,controller 126 may aggregate this information into a list of activechannels 616 in a network. Then, controller 126 may provide the list ofactive channels 616 that are used by radio nodes 110 to radio nodes 110.

Moreover, after receiving the list of active channels 616, interfacecircuit 610 may provide the list of active channels 616 to an interfacecircuit 618 in radio node 110-1. Next, interface circuit 618 may providethe list of active channels 616 to electronic device 112. For example,the list of active channels 616 may be provided to electronic device 112using wireless communication.

Furthermore, after receiving the list of active channels 616, electronicdevice 112 may perform a wireless scan 620 based at least in part on thelist of active channels 616.

While FIG. 6 illustrates communication between components usingunidirectional or bidirectional communication with lines having singlearrows or double arrows, in general the communication in a givenoperation in this figure may involve unidirectional or bidirectionalcommunication.

In some embodiments of the communication techniques, a controlleraggregates and then disseminates a list of active channels. This isillustrated in FIG. 7, which presents a drawing illustrating an exampleof a technique for providing a list of active channels 714 used by CBSDs710 in the CBRS. Notably, CBSDs 710 may provide information specifyingchannels that are used by CBSDs 710 in a network to controller 126.After receiving the information, controller 126 may aggregate theinformation about channels into the list of active channels (such as f₁,f₂, f₃ and f₄), which is then provided to CBSDs 710. Using CBSD 710-1 asan example, after receiving the list of active channels, CBSD 710-1 mayprovide the list of active channels to an electronic device (such aselectronic device 112 in FIG. 1).

In some embodiments, the communication techniques are used for neighborchannel discovery. Notably, the CBRS band is a conditionally freespectrum for electronic devices to transmit over the air. Each CBSD(such as an eNodeB) can get spectrum within the allowed 150 MHzbandwidth. Depending up on the size of a channel being used by a givenCBSD, there may be up to 30 channels in a venue.

In traditional cellular communications only handful of channels may beavailable for transmission for an operator or in a deployment. Eachtransmitting electronic device may be manually provisioned with thespecific list and the list may be broadcasted over the air in systeminformation (SIBs). This list may be used by electronic devices formeasurement purposes, which is used for handover decisions when anelectronic device is going out of the coverage of a serving cell. Thislist may also used by an electronic device for joining the network afterit wakes up from idle mode and for reselecting the best eNodeB forconnecting to the network.

Because the channel list in a CBRS network may be long and the channelsare dynamically allocated, statically provisioning all possible 30channels may result in inefficiency in the network, because anelectronic device may spend more time scanning other channels. In turn,this may result in an adverse communication-performance impact on theelectronic device, such as throughput degradation and reduced batteryoperating time.

The disclosed communication techniques may address these problems in adistributed manner and/or a centralized manner. In a distributedapproach, each CBSD may learn the list of channels available in thedeployment and may broadcast this information to the electronicdevice(s) that are connected to a network. This information may beupdated whenever there is a change in the network, such as when a newchannel is added or when a channel in an existing list is relinquished.

In a centralized approach, each radio node may publish the channel(s)they are using for transmitting to a centralized management entity, suchas a computer or a controller. The centralized management entity mayconsolidate or aggregate this information and may update each radio nodewith the resulting list. Note that the centralized management entity mayperform this operation whenever there is a change in the network, suchas when a new channel is added or when an existing channel is released.Moreover, upon receiving this information, each radio node may broadcastit in the system information to the electronic device(s) that areconnected to a network.

A variety of techniques may be used in the communication techniques. Forexample, the learning in the distributed approach may be spectrum-querybased. Notably, the CBRS architecture may include a SAS and CBSDs. TheSAS may be responsible for managing the spectrum and the CBSDs may usethe spectrum. Moreover, each CBSD may request a grant for a specificchannel and the SAS may provide the grant if the requested spectrum isavailable. As part of the SAS-CBSD protocol, a CBSD may periodicallyquery the SAS for the available spectrum within the whole CBRS band(which is 150 MHz). This procedure is sometimes referred to as a‘spectrum inquiry.’

Once the SAS returns the list of available channels, each CBSD may usesthis list to perform a network listen. Using the network listenprocedure, each CBSD can discover the existence of one or more otherCBSDs. Moreover, once the CBSDs are discovered during this process, thelist of channels in use may be recorded. At the end of the discoveryprocess, the discovered list may be advertised to the electronicdevice(s) in the system information.

As shown in FIG. 8, which presents a drawing illustrating an example ofchannel discovery, in some embodiments learning may be based at least inpart on already established neighbor relationships. For example, CBSDs810 may have one or more neighbors. Moreover, CBSDs 810 may exchange,with their neighbors, information that specifies the channel that theyare using. Over a period of time, each of CBSDs 810 may have thecomplete channel-usage information within the network. Using thisinformation, each of CBSDs 810 may derive the channel list that needs tobe broadcasted in the system information for the electronic device(s).

Furthermore, as shown in FIG. 9, which presents a drawing illustratingan example of channel discovery, in some embodiments multicast-baseddiscovery is used. Notably, each of CBSDs 910 may advertise its channelusage in a multicast message. The CBSDs 910 listening to the multicastmessage may get to know the channel information within the network.Using this information, each of CBSDs 910 may prepare a channel listthat is broadcast in the system information for the electronicdevice(s).

In some embodiments, one or more of the preceding techniques may be usedin the distributed approach and/or the centralized approach to aggregatea larger list. In order to optimize further, each CBSD may use networklisten for further filtering. For example, a first level list may beprepared as discussed previously, which may then be used as an input toa network-listen module. Note that some of the CBSDs using the channelsmay be too far from one that is performing a network listen. These CBSDsmay be filtered out if the network listen cannot find them. However, thechannels of the CBSDs that are discovered using the network listen maybe used to prepare a second list. Alternatively or additionally, thelist may be pruned based at least in part on a received signal strengthof each discovered CBSD. This criterion may be used to prune or filterout too CBSDs that are located far away. An output of this process maybe used to update the system information that is broadcast to theelectronic device(s).

We now describe embodiments of an electronic device, which may performat least some of the operations in the communication techniques. FIG. 10presents a block diagram illustrating an example of an electronic device1000 in accordance with some embodiments, such as one of radio nodes110, electronic device 112 computer 124. This electronic device includesprocessing subsystem 1010, memory subsystem 1012, and networkingsubsystem 1014. Processing subsystem 1010 includes one or more devicesconfigured to perform computational operations. For example, processingsubsystem 1010 can include one or more microprocessors, graphicsprocessing units (GPUs), ASICs, microcontrollers, programmable-logicdevices, and/or one or more digital signal processors (DSPs).

Memory subsystem 1012 includes one or more devices for storing dataand/or instructions for processing subsystem 1010 and networkingsubsystem 1014. For example, memory subsystem 1012 can include dynamicrandom access memory (DRAM), static random access memory (SRAM), and/orother types of memory. In some embodiments, instructions for processingsubsystem 1010 in memory subsystem 1012 include: one or more programmodules or sets of instructions (such as program module 1022 oroperating system 1024), which may be executed by processing subsystem1010. Note that the one or more computer programs or program modules mayconstitute a computer-program mechanism. Moreover, instructions in thevarious modules in memory subsystem 1012 may be implemented in: ahigh-level procedural language, an object-oriented programming language,and/or in an assembly or machine language. Furthermore, the programminglanguage may be compiled or interpreted, e.g., configurable orconfigured (which may be used interchangeably in this discussion), to beexecuted by processing subsystem 1010.

In addition, memory subsystem 1012 can include mechanisms forcontrolling access to the memory. In some embodiments, memory subsystem1012 includes a memory hierarchy that comprises one or more cachescoupled to a memory in electronic device 1000. In some of theseembodiments, one or more of the caches is located in processingsubsystem 1010.

In some embodiments, memory subsystem 1012 is coupled to one or morehigh-capacity mass-storage devices (not shown). For example, memorysubsystem 1012 can be coupled to a magnetic or optical drive, asolid-state drive, or another type of mass-storage device. In theseembodiments, memory subsystem 1012 can be used by electronic device 1000as fast-access storage for often-used data, while the mass-storagedevice is used to store less frequently used data.

Networking subsystem 1014 includes one or more devices configured tocouple to and communicate on a wired and/or wireless network (i.e., toperform network operations), including: control logic 1016, an interfacecircuit 1018 and one or more antennas 1020 (or antenna elements). (WhileFIG. 10 includes one or more antennas 1020, in some embodimentselectronic device 1000 includes one or more nodes, such as antenna nodes1008, e.g., a pad, which can be coupled to the one or more antennas1020, or nodes 1006, which can be coupled to a wired or opticalconnection or link. Thus, electronic device 1000 may or may not includethe one or more antennas 1020. Note that the one or more nodes 1006and/or antenna nodes 1008 may constitute input(s) to and/or output(s)from electronic device 1000.) For example, networking subsystem 1014 caninclude a Bluetooth™ networking system, a cellular networking system(e.g., a 3G/4G/5G network such as UMTS, LTE, etc.), a universal serialbus (USB) networking system, a networking system based on the standardsdescribed in IEEE 802.11 (e.g., a Wi-Fi® networking system), an Ethernetnetworking system, and/or another networking system.

Note that a transmit or receive antenna pattern (or antenna radiationpattern) of electronic device 1000 may be adapted or changed usingpattern shapers (such as reflectors) in one or more antennas 1020 (orantenna elements), which can be independently and selectivelyelectrically coupled to ground to steer the transmit antenna pattern indifferent directions. Thus, if one or more antennas 1020 include Nantenna pattern shapers, the one or more antennas may have 2^(N)different antenna pattern configurations. More generally, a givenantenna pattern may include amplitudes and/or phases of signals thatspecify a direction of the main or primary lobe of the given antennapattern, as well as so-called ‘exclusion regions’ or ‘exclusion zones’(which are sometimes referred to as ‘notches’ or ‘nulls’). Note that anexclusion zone of the given antenna pattern includes a low-intensityregion of the given antenna pattern. While the intensity is notnecessarily zero in the exclusion zone, it may be below a threshold,such as 3 dB or lower than the peak gain of the given antenna pattern.Thus, the given antenna pattern may include a local maximum (e.g., aprimary beam) that directs gain in the direction of electronic device1000 that is of interest, and one or more local minima that reduce gainin the direction of other electronic devices that are not of interest.In this way, the given antenna pattern may be selected so thatcommunication that is undesirable (such as with the other electronicdevices) is avoided to reduce or eliminate adverse effects, such asinterference or crosstalk.

Networking subsystem 1014 includes processors, controllers,radios/antennas, sockets/plugs, and/or other devices used for couplingto, communicating on, and handling data and events for each supportednetworking system. Note that mechanisms used for coupling to,communicating on, and handling data and events on the network for eachnetwork system are sometimes collectively referred to as a ‘networkinterface’ for the network system. Moreover, in some embodiments a‘network’ or a ‘connection’ between the electronic devices does not yetexist. Therefore, electronic device 1000 may use the mechanisms innetworking subsystem 1014 for performing simple wireless communicationbetween the electronic devices, e.g., transmitting advertising or beaconframes and/or scanning for advertising frames transmitted by otherelectronic devices as described previously.

Within electronic device 1000, processing subsystem 1010, memorysubsystem 1012, and networking subsystem 1014 are coupled together usingbus 1028. Bus 1028 may include an electrical, optical, and/orelectro-optical connection that the subsystems can use to communicatecommands and data among one another. Although only one bus 1028 is shownfor clarity, different embodiments can include a different number orconfiguration of electrical, optical, and/or electro-optical connectionsamong the subsystems.

In some embodiments, electronic device 1000 includes a display subsystem1026 for displaying information on a display, which may include adisplay driver and the display, such as a liquid-crystal display, amulti-touch touchscreen, etc.

Electronic device 1000 can be (or can be included in) any electronicdevice with at least one network interface. For example, electronicdevice 1000 can be (or can be included in): a desktop computer, a laptopcomputer, a subnotebook/netbook, a server, a tablet computer, asmartphone, a cellular telephone, a smartwatch, a consumer-electronicdevice, a portable computing device, an access point, a transceiver, arouter, a switch, communication equipment, an eNodeB, a controller, testequipment, and/or another electronic device.

Although specific components are used to describe electronic device1000, in alternative embodiments, different components and/or subsystemsmay be present in electronic device 1000. For example, electronic device1000 may include one or more additional processing subsystems, memorysubsystems, networking subsystems, and/or display subsystems.Additionally, one or more of the subsystems may not be present inelectronic device 1000. Moreover, in some embodiments, electronic device1000 may include one or more additional subsystems that are not shown inFIG. 10. Also, although separate subsystems are shown in FIG. 10, insome embodiments some or all of a given subsystem or component can beintegrated into one or more of the other subsystems or component(s) inelectronic device 1000. For example, in some embodiments program module1022 is included in operating system 1024 and/or control logic 1016 isincluded in interface circuit 1018.

Moreover, the circuits and components in electronic device 1000 may beimplemented using any combination of analog and/or digital circuitry,including: bipolar, PMOS and/or NMOS gates or transistors. Furthermore,signals in these embodiments may include digital signals that haveapproximately discrete values and/or analog signals that have continuousvalues. Additionally, components and circuits may be single-ended ordifferential, and power supplies may be unipolar or bipolar.

An integrated circuit (which is sometimes referred to as a‘communication circuit’) may implement some or all of the functionalityof networking subsystem 1014. The integrated circuit may includehardware and/or software mechanisms that are used for transmittingwireless signals from electronic device 1000 and receiving signals atelectronic device 1000 from other electronic devices. Aside from themechanisms herein described, radios are generally known in the art andhence are not described in detail. In general, networking subsystem 1014and/or the integrated circuit can include any number of radios. Notethat the radios in multiple-radio embodiments function in a similar wayto the described single-radio embodiments.

In some embodiments, networking subsystem 1014 and/or the integratedcircuit include a configuration mechanism (such as one or more hardwareand/or software mechanisms) that configures the radio(s) to transmitand/or receive on a given communication channel (e.g., a given carrierfrequency). For example, in some embodiments, the configurationmechanism can be used to switch the radio from monitoring and/ortransmitting on a given communication channel to monitoring and/ortransmitting on a different communication channel. (Note that‘monitoring’ as used herein comprises receiving signals from otherelectronic devices and possibly performing one or more processingoperations on the received signals)

In some embodiments, an output of a process for designing the integratedcircuit, or a portion of the integrated circuit, which includes one ormore of the circuits described herein may be a computer-readable mediumsuch as, for example, a magnetic tape or an optical or magnetic disk.The computer-readable medium may be encoded with data structures orother information describing circuitry that may be physicallyinstantiated as the integrated circuit or the portion of the integratedcircuit. Although various formats may be used for such encoding, thesedata structures are commonly written in: Caltech Intermediate Format(CIF), Calma GDS II Stream Format (GDSII) or Electronic DesignInterchange Format (EDIF). Those of skill in the art of integratedcircuit design can develop such data structures from schematics of thetype detailed above and the corresponding descriptions and encode thedata structures on the computer-readable medium. Those of skill in theart of integrated circuit fabrication can use such encoded data tofabricate integrated circuits that include one or more of the circuitsdescribed herein. While the preceding discussion used an Ethernet and anLTE communication protocol as an illustrative example, in otherembodiments a wide variety of communication protocols and, moregenerally, wireless communication techniques may be used. For example,instead of Ethernet, a communication protocol that is compatible withthe Internet Protocol is used. Thus, the communication techniques may beused in a variety of network interfaces. Furthermore, while some of theoperations in the preceding embodiments were implemented in hardware orsoftware, in general the operations in the preceding embodiments can beimplemented in a wide variety of configurations and architectures.Therefore, some or all of the operations in the preceding embodimentsmay be performed in hardware, in software or both. For example, at leastsome of the operations in the communication techniques may beimplemented using program module 1022, operating system 1024 (such as adriver for interface circuit 1018) or in firmware in interface circuit1018. Thus, the communication techniques may be implemented at runtimeof program module 1022. Alternatively or additionally, at least some ofthe operations in the communication techniques may be implemented in aphysical layer, such as hardware in interface circuit 1018.

While examples of numerical values are provided in the precedingdiscussion, in other embodiments different numerical values are used.Consequently, the numerical values provided are not intended to belimiting.

While the preceding embodiments illustrated the use of the communicationtechniques with CBRS (e.g., a frequency band near 3.5 GHz), in otherembodiments of the communication techniques different wireless signalsand/or different frequency band(s) may be used. For example, thewireless signals may be communicated in one or more bands offrequencies, including: 900 MHz, 2.4 GHz, 5 GHz, 60 GHz, and/or a bandof frequencies used by LTE or another cellular-telephone communicationprotocol.

In the preceding description, we refer to ‘some embodiments.’ Note that‘some embodiments’ describes a subset of all of the possibleembodiments, but does not always specify the same subset of embodiments.

The foregoing description is intended to enable any person skilled inthe art to make and use the disclosure, and is provided in the contextof a particular application and its requirements. Moreover, theforegoing descriptions of embodiments of the present disclosure havebeen presented for purposes of illustration and description only. Theyare not intended to be exhaustive or to limit the present disclosure tothe forms disclosed. Accordingly, many modifications and variations willbe apparent to practitioners skilled in the art, and the generalprinciples defined herein may be applied to other embodiments andapplications without departing from the spirit and scope of the presentdisclosure. Additionally, the discussion of the preceding embodiments isnot intended to limit the present disclosure. Thus, the presentdisclosure is not intended to be limited to the embodiments shown, butis to be accorded the widest scope consistent with the principles andfeatures disclosed herein.

What is claimed is:
 1. A radio node, comprising: a first node orconnector configured to communicatively couple to an antenna; a secondnode or connect configured to communicatively couple to a network; afirst interface circuit, communicatively coupled to the first node orconnector, configured to communicate using wireless communication; asecond interface circuit, communicatively coupled to the second node orconnector, configured to communicate with one or more second radio nodesin the network, wherein the radio node is configured to: listen, usingthe first interface circuit, for transmissions associated with the oneor more second radio nodes; determine, based at least in part on thetransmissions, a first list of discovered channels associated with theradio node and the one or more second radio nodes; provide, using thesecond interface circuit, the first list of discovered channelsaddressed to the one or more second radio nodes; receive, using thesecond interface circuit, one or more second lists of discoveredchannels associated with the one or more second radio nodes; aggregatethe first list of discovered channels and the second list of discoveredchannels into a list of active channels; and provide, using the firstinterface circuit, the list of active channels addressed to anelectronic device.
 2. The radio node of claim 1, wherein the radio nodeis configured to provide the list of first discovered channels using amulticast message.
 3. The radio node of claim 1, wherein the networkcomprises a small cell.
 4. The radio node of claim 1, wherein thechannels comprise portions of a spectrum in a shared-license-access bandof frequencies.
 5. The radio node of claim 4, wherein the channels areincluded in a Citizens Broadband Radio Service.
 6. The radio node ofclaim 1, wherein the radio node is configured to provide, using thesecond interface circuit, the list of discovered channels, the list ofactive channels or both addressed to a computer.
 7. The radio node ofclaim 6, wherein the computer comprises a controller for the radio nodeand the one or more second radio nodes.
 8. The radio node of claim 6,wherein the computer is different from a spectrum allocation server. 9.The radio node of claim 1, wherein the second interface circuit isconfigured to use wired communication.
 10. The radio node of claim 1,wherein the radio node comprises: an Evolved Node B (eNodeB), aUniversal Mobile Telecommunications System (UMTS) NodeB and radionetwork controller (RNC), or a New Radio (NR) gNB or gNodeB.
 11. Anon-transitory computer-readable storage medium for use in conjunctionwith a radio node, the computer-readable storage medium storing programinstructions that, when executed by the radio node, cause the radio nodeto perform operations comprising: listening for transmissions associatedwith one or more second radio nodes in a network; determining, based atleast in part on the transmissions, a first list of discovered channelsassociated with the radio node and the one or more second radio nodes;providing the first list of discovered channels addressed to the one ormore second radio nodes; receiving one or more second lists ofdiscovered channels associated with the one or more second radio nodes;aggregating the first list of discovered channels and the second list ofdiscovered channels into a list of active channels; and providing thelist of active channels addressed to an electronic device.
 12. Thenon-transitory computer-readable storage medium of claim 11, wherein thelist of first discovered channels is provided using a multicast message.13. The non-transitory computer-readable storage medium of claim 11,wherein the network comprises a small cell.
 14. The non-transitorycomputer-readable storage medium of claim 11, wherein the channelscomprise portions of a spectrum in a shared-license-access band offrequencies.
 15. The non-transitory computer-readable storage medium ofclaim 14, wherein the channels are included in a Citizens BroadbandRadio Service.
 16. The non-transitory computer-readable storage mediumof claim 11, wherein the operations comprise providing the list ofdiscovered channels, the list of active channels or both addressed to acomputer.
 17. The non-transitory computer-readable storage medium ofclaim 16, wherein the computer comprises a controller for the radio nodeand the one or more second radio nodes.
 18. The non-transitorycomputer-readable storage medium of claim 16, wherein the computer isdifferent from a spectrum allocation server.
 19. A method foraggregating a list of active channels, comprising: by a radio node:listening for transmissions associated with one or more second radionodes in a network; determining, based at least in part on thetransmissions, a first list of discovered channels associated with theradio node and the one or more second radio nodes; providing the firstlist of discovered channels addressed to the one or more second radionodes; receiving one or more second lists of discovered channelsassociated with the one or more second radio nodes; aggregating thefirst list of discovered channels and the second list of discoveredchannels into the list of active channels; and providing the list ofactive channels addressed to an electronic device.
 20. The method ofclaim 19, wherein the list of first discovered channels is providedusing a multicast message.